The present invention relates generally to bi-directional electronic communication systems, and more particularly to a system and method for assigning unique network addresses to mobile platforms for use in bi-directional communications between the mobile platforms and a satellite system.
In order to communicate within or between networks, a transmitting device must be able to determine a particular network address associated with a receiving device in order to transmit data to that receiving device. The transmitting device also must have a network address in order for the network to determine the data route for a particular transmission. The address may be a unique static address or may be a dynamically assigned address. However, regardless of the manner of assignment of the network address, it is typically used to specifically identify a particular network, and usually a specific device within the network.
Various types of network address may be provided, including for example, an Internet address, a home page address or an email address. Typically, switches and routers use the network address to transmit data (e.g., data packets) to the destination network address. For example, an Internet Protocol (IP) address specifically identifies the source and destination of data transmitted, which data is typically provided as data packets across networks. The IP address may include a network address portion and a specific device address portion. Thus, in operation, switches select the data paths for transmitting data packets to their destination with routers determining the next network point to which the data packets should be transmitted.
Without a proper address, such as an IP address, devices are unable to determine the destination for specific data packets and are unable to transmit that data. Therefore, each device that sends and receives data within a network is assigned a network address in order for it to be recognized within the network, as well as outside the network (i.e., for providing the necessary address information to transmit data to and receive data from that device).
Network addresses, and more particularly, IP addresses, may be assigned in various ways. One way is for the information technology (IT) department or information services (IS) department of an organization to assign each computer within that organization a specific IP address, with an individual loading the information onto each computer. This occurs on-site with the IP address of each computer configured at the time of installation and/or upon reformatting of the computer (e.g., after a computer is reset because of network of other connection problems). Alternately, the computers may be configured such that IP addresses are assigned dynamically when needed for electronic communication (e.g., when accessing the Internet using a network server).
Sometimes it is desirable to remotely assign a network address to a device. For example, an Internet Service Provider (ISP) constantly identifies user logins in order to dynamically assign IP addresses to the computers or other electronic devices of individuals using, for example, landlines (e.g., dial-up with a modem) to dial into the ISP network. The ISP can directly establish a connection between the user""s computer and the ISP network in order to obtain access to the Internet using the landline on which the user dialed in. Thus, the ISP is able to easily identify the connection path of the user and assign an IP address because the user is stationary and accessing the ISP using a specific telephone landline.
A problem occurs when the location of the user is not known, for example, if the user attempts to login remotely or wirelessly while in-transit. When in-transit, the location of the user may have to be determined in order to establish an initial communication link and assign an IP address for bi-directional network communication. An additional problem associated with logging in while in-transit is the cost of connecting to a network system. When communicating electronically while in-transit (e.g., using a satellite system), the cost for that connection (i.e., bandwidth) is extremely high. For example, because the available bandwidth is substantially less when using a satellite communication than when using a ground-based communication system, the cost of transmitting data is much higher. Presently, the cost of satellite communication may exceed 1000 times the cost of ground-based communication. Thus, even a small increase in the efficiency at which an in-transit user can be identified and assigned an IP address, which reduces the bandwidth usage needed to assign that network address, will result in enormous cost savings. This is particularly true as the number of in-transit users increases.
The present invention provides a system and method for assigning a unique network address (e.g., IP address) to a mobile platform, thereby providing for differentiation between each mobile platform during bi-directional electronic communications. Once an IP address is assigned, unicast messages may be transmitted to a specific mobile platform having an assigned IP address.
In one preferred embodiment, a ground system assigns a unique subnet address to each mobile platform at the time of the activation of an electronic communication system on-board the mobile platform, or upon initial installation and/or upon replacement of equipment (e.g., due to equipment failure) requiring the IP address. This eliminates the need for a maintenance person to load this data onto the equipment, thereby reducing the chance of the maintenance person incorrectly entering part of the IP address. It also reduces cost by eliminating the need for training individuals on how to configure the equipment with the IP address, as well as the manual operation of configuring the equipment.
Upon initial activation of a communication system on-board a mobile platform requiring an IP address, the ground system typically is not able to transmit a unicast signal to the communication system equipment within the mobile platform because the IP address is not assigned. In one embodiment of the present invention, IP address information is embedded into a polling signal that is multicast to all mobile platforms (e.g., aircrafts) using a forward communication path. Because the systems on-board the mobile platforms are not yet configured, and thus unable to establish a return communication path because no IP address is assigned, each of the mobile platforms will receive the embedded information before it is required for use. More preferably, the present invention is configured such that a signal containing the IP address for a particular mobile platform is not transmitted until the mobile platform requests the IP address from a ground system.
The signal having the IP address therein is multicast to mobile platforms (e.g., aircrafts) within a coverage region of the satellites used by the ground system, and includes other information, including specifically a mobile platform code or identifier for use by the mobile platform requesting the IP address to identify the particular multicast signal containing its network address. Upon receiving the signal assigning the IP address, the mobile platform preferably transmits a confirmation signal using the assigned address.
The invention preferably also provides for copying or mirroring the assigned IP address information to other equipment or components on-board the mobile platform (e.g., servers and antennas). Thus, even if a data transmitter/receiver on the mobile platform fails and must be replaced, upon activation of the replacement equipment, the assigned IP address may be obtained from the other on-board equipment. This further minimizes the possibility of having to transmit IP address information after the initial IP address assignment.
A more preferred IP address information signal contains the assigned network address and a subnet mask. This provides for communication with specific equipment on-board the mobile platform. For example, the ground system will then be able to unicast data directly to specific equipment (e.g., a server) on-board the mobile platform using a satellite system.
Thus, the present invention provides an efficient system and method for assigning IP addresses to mobile platforms communicating with a satellite system by identifying the specific mobile platform requiring an IP address assignment. By reducing the bandwidth-requirement for assigning the IP addresses, cost is reduced. Mirroring the information to other equipment on-board the mobile platform also reduces the risk of having to re-transmit IP address assignment information after the initial transmission.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.